Expression of HIP/PAP in hepatocellular carcinoma and effect of siRNA on migration and invasion in HCC cells

The Parkinson's disease-associated protein α-synuclein inhibits hepatoma by exosome delivery

Numerous epidemiological studies suggest a link between Parkinson's disease (PD) and cancer. However, their relevant pathogenesis is not clear. In the present study, we investigated the potential role of exosome-delivered α-synuclein (α-syn) in the regulation between PD and liver cancer. We cultured hepatocellular carcinoma (HCC) cells with exosomes derived from conditioned medium of the PD cellular model, and injected exosomes enriched with α-syn into the striatum of a liver cancer rat model. We found that α-syn-contained exosomes from the rotenone-induced cellular model of PD suppressed the growth, migration, and invasion of HCC cells. Integrin αVβ5 in exosomes from the rotenone-induced PD model was higher than that in the control, resulting in more α-syn-contained exosomes being taken up by HCC cells. Consistently, in vivo experiments with rat models also confirmed exosome-delivered α-syn inhibited liver cancer. These findings illustrate the important role of PD-associated protein α-syn inhibiting hepatoma by exosome delivery, suggesting a new mechanism underlying the link between these two diseases and therapeutics of liver cancer.

Anti-tumor effect of single-chain antibody to Reg3a in colorectal cancer

BACKGROUND

Regenerating protein 3a (Reg3a) is a trophic factor that functions as a stimulus in cell proliferation and neogenesis. Previous studies showed that Reg3a is ectopically upregulated in a majority of colorectal cancers (CRC) and detectable in the serum.

METHODS

Single-chain variable fragment targeting Reg3a (scFv-Reg3a) was screened from a phage library. The bioactivity of recombinant Reg3a (rReg3a) and scFv-Reg3a were tested in LoVo and RKO cell lines using MTT, flow cytometry, wound healing and transwell analyses. Whether scFv-Reg3a inhibits tumor growth and enhances 5-fluorouracil (5-FU)-caused cell death were further examined in LoVo cell-transplanted nude BALB/c mice.

RESULTS

A scFv-Reg3a from clone C2 was obtained and its binding affinity (KD) to rReg3a was determined to be 4.44 × 10^-10. In cultured LoVo and RKO cells, rReg3a promoted but scFv-Reg3a inhibited cell proliferation, survival, migration and invasion. In LoVo cell-xenografted nude mice, administration of rReg3a accelerated tumor growth while scFv-Reg3a suppressed cell proliferation and reinforced 5-FU-induced cell death.

CONCLUSION

The newly developed scFv-Reg3a is an anti-cancer agent which is potent to suppress CRC cell proliferation and survival. The use of scFv-Reg3a could enhance the effectiveness of 5-FU-based chemotherapy in the cancerous treatment.

Role of Regenerating Islet-Derived Protein 3A in Gastrointestinal Cancer

Regenerating islet-derived protein 3A (Reg3A), a protein mainly expressed in the digestive system, has been found over-expressed in many kinds of gastrointestinal cancer, including hepatocellular carcinoma, pancreatic cancer, gastric cancer, and colorectal cancer, therefore has been considered as a promising tumor marker. In recent years, considerable attention has been focused on the tumorigenesis effects of Reg3A, which were mainly manifested as cell proliferation promotion, cell apoptosis inhibition, the regulation of cancer cell migration and invasion. In particular, based on the significant up-regulation of Reg3A during pancreatic inflammation as well as its tumorigenic potential, Reg3A has been considered to play a key role in inflammation-linked pancreatic carcinogenesis. In addition, we here systematically generalized the reported Reg3A-related signaling molecules, which included JAK2-STAT3- NF-κB, SOCS3, EXTL3-PI3K-Akt, GSK3β, Wnt/β-catenin as well as some invasion and migration-related genes (Snail, MMP-2, MMP-9, E-cadherin, RhoC, and MTA1). And gp130, EGFR, EXTL3, and Fibronectin 1 might act as potential receptors for Reg3A.

Comparative Analysis of Expression Profiles of Reg Signaling Pathways-Related Genes Between AHF and HCC

Regenerating islet-derived protein (Reg) could participate in the occurrence of diabetes mellitus, inflammation, tumors, and other diseased or damaged tissues. However, the correlation of Reg with acute hepatic failure (AHF) and hepatocellular carcinoma (HCC) is poorly defined. To reveal the expression profiles of Reg family and their possible regulatory roles in AHF and HCC, rat models of HCC and AHF were separately established, and Rat Genome 230 2.0 was used to detect expression profiles of Reg-mediated signaling pathways-associated genes from liver tissues in AHF and HCC. The results showed that a total of 79 genes were significantly changed. Among these genes, 67 genes were the AHF-specific genes, 45 genes were the HCC-specific genes, and 33 genes were the common genes. Then, K-means clustering classified these genes into 4 clusters based on the gene expression similarity, and DAVID analysis showed that the above altered genes were mainly associated with stress response, inflammatory response, and cell cycle regulation. Thereafter, IPA software was used to analyze potential effects of these genes, and the predicted results suggested that the Reg-mediated JAK/STAT, NF-κB, MAPK (ERK1/2, P38 and JNK), PLC, and PI3K/AKT signaling pathways may account for the activated inflammation and cell proliferation, and the attenuated apoptosis and cell death during the occurrence of AHF and HCC.